A community study of bees visiting flowers with poricidal anthers was made in the subtropical Araucaria forest region of Rio Grande do Sui, Brazil. Bees of 79 species, representing about 40% of the taxa occurring at the study site, were collected on 19 species of flowering plants with poricidal anthers of the families Melas­tomataceae and Solanaceae, The majority of flower visitors were able to buzz (sonicate) to release pollen, Buzzing is thought to be the only mode of pollen collection that results in polli­nation, No oligolectic bee-plant relation based on buzz pollination was detected, Most bees were not specialized to forage on plants with poricidal anthers, According to the abundance of visitors at specific flowers, three major groups of buzz pollinators could be distin­guished; these were bumble bees, stingless bees of the genus MeliPona and halictid bees, The pollen sources mainly exploited by them differ in flower structure, flowering syndrome and forest stratum, Therefore, the structure of the bee community seems to be closely related to the composition of the local vegetation, The extent to which bees of a species show prefer­ence for poricidal flowers, however, is more dependent on habitat than on plant taxa, The evolution of buzzing behaviour by female bees to maximize pollen harvest may have preceded the appearance of poricidal anthers and the syn­drome of buzz pollination.